Vaibhav Rajan 

Assistant Professor
Department of Information Systems and Analytics
School of Computing
National University of Singapore

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Education:

  • PhD, Computer Science (2008 - 2012)
    • Swiss Federal Institute of Technology (EPFL), Lausanne, Switzerland
    • Topic: Algorithms and Statistical Methods in Large-Scale Phylogeny Inference
    • Advisor: Professor Bernard Moret
  • MS, Computer Science, EPFL, Switzerland (2006 - 2008)
  • BE, Computer Science, BITS, Pilani, India (2000 - 2004)
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Professional Appointments:
  • Assistant Professor, School of Computing, National University of Singapore
  • Chief Data Scientist (Founding Member), VideoKen (2017)
  • Visiting Faculty Member, IIIT-B (2016 - 2017)
  • Senior Research Scientist, Xerox Research Centre India (2016)
  • Research Scientist, Xerox Research Centre India (2012 - 2015)
  • Research Engineer, Hewlett Packard Labs (2004 - 2006)

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Research:

Technical interests: Algorithms, Statistics, Machine Learning 

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Reviewer/Program Committee Member: 

AAAI 2017, IJCAI 2016, ACM CODS (2015, 2016, 2017), Data Mining and Knowledge Discovery (ECML Journal Track)

Organizing Committee Member

XRCI Open 2016, PACC (part of PAKDD 2016), ACM CODS-COMAD 2018

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Peer-reviewed Publications and Patents

Machine Learning/Computational Statistics

3. Vine Copulas for Mixed Data: Multi-view Clustering for Mixed Data Beyond Meta-Gaussian Dependencies, Lavanya Sita Tekumalla, Vaibhav Rajan, Chiranjib Bhattacharyya, Machine Learning (Springer), 2017, 1-27.

2. Dependency Clustering of Mixed Data with Gaussian Mixture Copulas, Vaibhav Rajan, Sakyajit Bhattacharya, 25th International Joint Conference on Artificial Intelligence IJCAI 2016, New York, USA

1. Unsupervised Learning using Gaussian Mixture Copula Model, Sakyajit Bhattacharya, Vaibhav Rajan, 21st International Conference on Computational Statistics COMPSTAT 2014, Geneva, Switzerland 

(Won us the ERS IASC Young Researchers Award 2014 for best paper by researchers under 35 given by the European Regional Section (ERS) of the International Association for Statistical Computing (IASC)).

Machine Learning in Healthcare

8. Prediction and Imputation in Irregularly Sampled Clinical Time Series Data using Hierarchical Linear Dynamical Models, Abhishek Sengupta, Prathosh AP, Satya Narayan Shukla, Vaibhav Rajan, Chandan K Reddy, 39th Annual International Conference of the IEEE Engineering in Medicine and Biology Society IEEE EMBC 2017, JeJu Island, S. Korea. 

7. ICU Mortality Prediction: A Classification Algorithm for Imbalanced Datasets, Sakyajit Bhattacharya, Vaibhav Rajan, Harsh Shrivastava, 31st AAAI Conference on Artificial Intelligence AAAI 2017, San Francisco, USA

6. Predicting Complications in Critical Care using Heterogeneous Clinical Data, Vijay Huddar, Bapu Koundinya Desiraju, Vaibhav Rajan, Sakyajit Bhattacharya, Shourya Roy, Chandan K Reddy, Special Section on Big Data Analytics for Smart and Connected Health, IEEE Access 4, 7988-8001, 2016.

5. A Statistical Model for Stroke Outcome Prediction and Treatment Planning, Abhishek Sengupta, Vaibhav Rajan, Sakyajit Bhattacharya, GRK Sarma, 38th Annual International Conference of the IEEE Engineering in Medicine and Biology Society IEEE EMBC 2016, Orlando, USA. 

4. Clinical Decision Support for Stroke using Multiview Learning based Models for NIHSS Scores, Vaibhav Rajan, Sakyajit Bhattacharya, Ranjan Shetty, Amith Sitaram, Vivek G Raman, PAKDD 2016 Workshop: Predictive Analytics in Critical Care (PACC), Auckland, New Zealand.

3. Classification with Imbalance: A Similarity based Method for Predicting Respiratory Failure, Harsh Shrivastava, Vijay Huddar, Sakyajit Bhattacharya, Vaibhav Rajan, IEEE International Conference on Bioinformatics and Biomedicine IEEE BIBM 2015, Washington DC, USA.

2. A Novel Classification Method for Predicting Acute Hypotensive Episodes in Critical Care, Sakyajit Bhattacharya, Vaibhav Rajan, Vijay Huddar, 5th ACM Conference on Bioinformatics, Computational Biology and Health Informatics ACM BCB 2014, Newport Beach, USA.

1. Predicting Postoperative Acute Respiratory Failure in Critical Care using Nursing Notes and Physiological Signals, Vijay Huddar, Vaibhav Rajan, Sakyajit Bhattacharya, Shourya Roy, 36th Annual International Conference of IEEE Engineering in Medicine and Biology Society IEEE EMBC 2014, Chicago, USA.

Machine Learning in Crowdsourcing

7. Crowds of Crowds: Performance based Modeling and Optimization over Multiple Crowdsourcing Platforms, Sakyajit Bhattacharya, Laura Elisa Celis, Deepthi Chander, Koustuv Dasgupta, Saraschandra Karanam, Vaibhav Rajan, Human Computation (2015) 2:1:105-131. 

6. CrowdUtility: A Recommendation System for Crowdsourcing Platforms, Deepthi Chander, Sakyajit Bhattacharya, L. Elisa Celis, Koustuv Dasgupta, Saraschandra Karanam, Vaibhav Rajan, Avantika Gupta, Conference on Human Computation & Crowdsourcing HCOMP 2014, Pittsburgh, USA.

5. Adaptive Performance Optimization over Crowd Labor Channels, Saraschandra Karanam, L. Elisa Celis, Deepthi Chander, Koustuv Dasgupta, Vaibhav Rajan, Conference on Human Computation & Crowdsourcing HCOMP 2014, Pittsburgh, USA.

4. CrowdControl: Online learning for optimal task scheduling on crowd platforms, Vaibhav Rajan, Sakyajit Bhattacharya, L Elisa Celis, Deepthi Chander, Koustuv Dasgupta, Saraschandra Karanam, 30th International Conference on Machine Learning ICML 2013 Workshop: Machine Learning Meets Crowdsourcing, Atlanta, USA.

3. Understanding Dynamic Performance Variability Across Multiple Crowdsourcing Platforms, Saraschandra Karanam, Vaibhav Rajan, Koustuv Dasgupta, Short Paper, ACM Web Science 2013, Paris, France.

2. Adaptive Crowdsourcing for Temporal CrowdsLaura Elisa Celis, Koustuv Dasgupta and Vaibhav Rajan, 3rd Temporal Web Analytics Workshop TempWeb at WWW 2013, Rio de Janeiro, Brazil.

1. CrowdUtility: Know The Crowd That Works For You, Dasgupta, K., Rajan, V., Karanam, S., Balamurugan, C. and Piratla, N.  Extended Abstracts, ACM SIGCHI Conference on Human Factors in Computing Systems CHI 2013, Paris, France.

Machine Learning in Bioinformatics

18. Analysis of gene copy number changes in tumor phylogenetics, Jun Zhou, Yu Lin, Vaibhav Rajan, William Hoskins, Jijun Tang, BMC Algorithms in Molecular Biology, 11:26, 2016.

17. Maximum parsimony analysis of gene copy number changes in tumor phylogenetics, Jun Zhou, Yu Lin, Vaibhav Rajan, William Hoskins, Jijun Tang, Proc. 15th Workshop on Algorithms in Bioinformatics WABI 2015, Atlanta (USA)

16. A method of alignment masking for refining the phylogenetic signal in multiple sequence alignments, Vaibhav Rajan, 
Molecular Biology and Evolution, Oxford University Press, 2013 Mar;30(3):689-712. doi: 10.1093/molbev/mss264. 

15. TIBA: A tool for phylogeny inference from rearrangement data with bootstrap analysis, Yu Lin*, Vaibhav Rajan*, BME Moret, Bioinformatics 2012 Dec 15;28(24):3324-5. doi: 10.1093/bioinformatics/bts603. 

14. Bootstrapping Phylogenies Inferred from Rearrangement Data, Yu Lin*, Vaibhav Rajan*, BME Moret, BMC Algorithms in Molecular Biology, 7:21,2012 (best papers from WABI '11).

13. Bootstrapping Phylogenies Inferred from Rearrangement Data. Yu Lin*, Vaibhav Rajan*, BME Moret, Proc. 11th Workshop on Algorithms in Bioinformatics WABI 2011, Saarbrucken (Germany), Lecture Notes in Computer Science 6833, 175-187, Springer Verlag (2011).

12. A metric for phylogenetic trees based on matching. Yu Lin, Vaibhav Rajan, BME Moret, Proc. 7th Int'l Symp. of Bioinformatics Research and Applications ISBRA 2011, Changsha (China).

11. A metric for phylogenetic trees based on matching, Yu Lin, Vaibhav Rajan, BME Moret, IEEE/ACM Transactions on Computational Biology and Bioinformatics9, 4 (2012), 1014-1022 (best papers from ISBRA'11).

10. Fast and accurate phylogenetic reconstruction from high-resolution whole-genome data and a novel robustness estimatorYu Lin, Vaibhav Rajan, BME Moret, Journal of Computational Biology 18, 9, 1131-1139 (2011) (special issue on RECOMB-CG'10).

9. Fast and accurate phylogenetic reconstruction from high-resolution whole-genome data and a novel robustness estimator, Yu Lin*, Vaibhav Rajan*, BME Moret, Proc. 8th RECOMB Workshop on Comparative Genomics RECOMB-CG 2010, Ottawa (Canada); in Lecture Notes in Computer Science 6398, 137-148, Springer Verlag (2010).

8. Estimating true evolutionary distances under rearrangements, duplications, and losses, Yu Lin, Vaibhav Rajan, Krister Swenson, BME Moret, BMC Bioinformatics 2010, 11(Suppl 1):S54doi:10.1186/1471-2105-11-S1-S54 (special issue on APBC'10).

7. Heuristics for the inversion median problem, Vaibhav Rajan*, A.W. Xu*, Yu Lin, Krister Swenson, BME Moret, BMC Bioinformatics 2010, 11(Suppl 1):S30doi:10.1186/1471-2105-11-S1-S30 (special issue on APBC'10).

6. Estimating true evolutionary distances under rearrangements, duplications, and lossesYu Lin, Vaibhav Rajan, Krister Swenson, BME Moret, Proc. 8th Asia-Pacific Bioinformatics Conference APBC 2010, Bangalore (India).

5. Heuristics for the inversion median problem, Vaibhav Rajan*, A.W. Xu*, Yu Lin, Krister Swenson, BME Moret, Proc. 8th Asia-Pacific Bioinformatics Conference APBC 2010, Bangalore (India).

4. Sorting signed permutations in O(nlogn) time, Krister Swenson, Vaibhav Rajan, Yu Lin, and Bernard Moret, Journal of Computational Biology. March 2010, 17(3): 489-501. doi:10.1089/cmb.2009.0184 (extended version of paper in RECOMB'09).

3. Hurdles and Sorting by Inversions: Combinatorial, Statistical and Experimental Results, Krister Swenson, Yu Lin, Vaibhav Rajan and Bernard Moret, Journal of Computational Biology. October 2009, 16(10): 1339-1351. doi:10.1089/cmb.2009.0156 (extended version of paper in RECOMB-CG'08).

2. Sorting signed permutations in O(nlogn) time, Krister Swenson, Vaibhav Rajan, Yu Lin and Bernard Moret, Proc. 13th International Conference on Research in Computational Molecular Biology RECOMB 2009, Tucson (USA); in Lecture Notes in Computer Science 5541, 386-399, Springer Verlag (2009).

1. Hurdles Hardly Have to be Heeded, Krister Swenson, Yu Lin, Vaibhav Rajan and Bernard Moret, Proc. 6th RECOMB Workshop on Comparative Genomics RECOMB-CG 2008, Paris (France); in Lecture Notes in Computer Science 5267, 239-249, Springer Verlag (2008).

Patents Granted

3. Predicting arrival times of vehicles based upon observed schedule adherence, Abhishek Tripathi, Vaibhav Rajan, Narayanan Unny Edakunni, Publication number: 2015-0269491, Oct 13, 2015 

2. Systems And Methods For Delivering Contents Using Broadcast Networks, Vaibhav Rajan, Ajay Gupta, Chandrasekar Venkataraman, Publication number: US2007/0237106 A1, Oct 11, 2007

1. Delivering Specific Contents to Specific Recipients using Broadcast Networks, Rahul Shukla, Ajay Gupta, Vaibhav Rajan, Publication number: WO2007/017887, Feb 15, 2007

Patents Filed

28. Method and System for Data Processing to Predict Health Condition of a Human Subject, Lavanya Tekumalla, Vaibhav Rajan

27. System and Method for Predicting Health Condition of a Patient, Harsh Shrivastava, Vijay Huddar, Sakyajit Bhattacharya, Vaibhav Rajan

26. Method and System to Process Electronic Medical Records for Predicting Health Conditions of Patients, Vaibhav Rajan, Vijay Huddar

25. Forecasting Patient Vital Measurements for Healthcare Analytics, Abhishek Sengupta, Bhupendra Solanki, Prathosh AP, Vaibhav Rajan, Katerina Sinclair, Stephen Fullerton, Satya Shukla 

24. Clustering High Dimensional Data using Gaussian Mixture Copula Model with Lasso based Regularization, Sakyajit Bhattacharya, Vaibhav Rajan, Asim Anand

23. Methods and Systems for Predicting Health Condition of A Human Subject, Lavanya Tekumalla, Vaibhav Rajan

22. System and Method of Modeling Irregularly Sampled Temporal Data using Kalman Filters, Abhishek Sengupta, Prathosh AP, Satya Shukla, Vaibhav Rajan, Katerina Sinclair, Stephen Fullerton

21. Method and System for Predicting Admission of a Human Subject to a Ward in a Medical Center, Vaibhav Rajan, Sakyajit Bhattacharya, Vijay Huddar, Abhishek Sengupta, James D Kirkendall, Stephen Fullerton, Katerina Sinclair, Bhupendra Singh Solanki, Prathosh AP

20. Method and System for Improved Machine Learning using Supervised Classification of Imbalanced Datasets with Overlap, Sakyajit Bhattacharya, Vaibhav Rajan

19. Method and Apparatus for Predicting Mortality of a Patient, Vijay Huddar, Bhupendra Solanki, Vaibhav Rajan, Sakyajit Bhattacharya

18. Method and System for Prediction of an Outcome of a Stroke Event, Abhishek Sengupta, Vaibhav Rajan, Sakyajit Bhattacharya, GRK Sarma

17. Assessing Patient Risk Of An Acute Hypotensive Episode with Vital Measurements, Sakyajit Bhattacharya, Vaibhav Rajan, Vijay Huddar

16. Methods and Systems for Predicting Mortality of a Patient, Sakyajit Bhattacharya, Vaibhav Raja, Harsh Shrivastava

15. Methods and Systems for Predicting Health Condition of A Human Subject, Lavanya Tekumalla, Vaibhav Rajan

14. Methods and Systems for Predicting Health Condition of A Human Subject, Vaibhav Rajan, Sakyajit Bhattacharya

13. System and Method for Predicting Health Condition of a Patient, Vijay Huddar, Vaibhav Rajan, Sakyajit Bhattacharya, Shourya Roy

12. Methods and Systems for Predicting Health Condition of Human Subjects, Vaibhav Rajan, Sakyajit Bhattacharya, Ranjan Shetty, Amith Sitaram, Vivek G Raman

11. Methods and Systems for Crowdsourcing Software Development Projects, Atul Singh, Vaibhav Rajan, Koustuv Dasgupta, Nischal Piratla 

10. Methods and Systems for Assigning Tasks to Workers, Saraschandra Karanam, Elisa Celis, Vaibhav Rajan, Koustuv Dasgupta, Deepthi Chander

9. Multimodal Monitoring Systems for Physical Activity, Kuldeep R, Vaibhav Rajan, Abhishek Kumar, Nischal Piratla

8. Methods and Systems for Predicting Health Condition of Human Subject, Vaibhav Rajan, Sakyajit Bhattacharya, Ranjan Shetty, Amith Sitaram, Vivek G Raman

7. Assessing Patient Risk of an Acute Hypotensive Episode, Vaibhav Rajan, Sakyajit Bhattacharya, Vijay Huddar

6. Methods and System for Analyzing Financial data, Sakyajit Bhattacharya, Vaibhav Rajan.

5. Methods and System for Analyzing Healthcare data, Sakyajit Bhattacharya, Vaibhav Rajan.

4. System and Method of Remote Determination of Acute Respiratory Infection, Vaibhav Rajan, Om Deshmukh, L K Mestha, Leslie Edward S Lewis, Survi Kyal, Beilei Xu, Nischal Piratla

3. Method and System for Selecting Task TemplatesSaraschandra Karanam, Koustuv Dasgupta, Harini Sampath, Vaibhav Rajan, Bipin Indurkhya

2. Method and System of Scheduling Allocation of Tasks, Vaibhav Rajan, Sakyajit Bhattacharya, Koustuv Dasgupta, Nischal Piratla, Elisa Celis, Deepthi Chander, Saraschandra Karanam

1.  Method and System for Recommending Crowdsourcing PlatformsKoustuv Dasgupta, Vaibhav Rajan, Kovendhan Ponnavaikko, Saraschandra Karanam